Women are more likely than men to lose interest in sex while in a longterm relationship, according to a new study.

The study published in the journal BMJ Open surveyed 4,839 British men and 6,669 women aged 16-74, and found that overall 15% of men and 34.2% of women reported lacking interest in sex for three months or more in the previous year. For both men and women, the reasons for lack of interest in sex varied, with some reporting that age, health, and depression affected their desire.

While both sexes lost some desire with age, women were more likely to lose interest in sex when living with a partner or while in a relationship lasting over a year, according to the study.

Both sexes reported that communication is key to keeping the spark alive. Men and women who found it "always easy to talk about sex" were less likely to report lack of sexual interest.

The study found that men and women who had partners with sexual difficulties or were unhappy in their relationship were more likely to report a disinterest in sex.

Likewise, women who were pregnant in the last year or had more than one young child reported lower interest in sex.

Cynthia Graham, the lead author of the study and professor of the Centre for Sexual Health Research at the University of Southampton said in a statement that the study showcases driving factors behind sexual interest in both men and women.

"For women in particular, the quality and length of relationship and communication with their partners are important in their experience of sexual interest," Graham said in a statement. "It highlights the need to assess and – if necessary – treat sexual interest problems in a holistic and relationship, as well as gender-specific way."